This invention relates to a burn-in apparatus.
Makers are required to find out, before shipment of products from a factory, initial failures of the products which may occur within one or two years after they have been delivered to and installed at a customer. To this end, burn-in apparatus have been developed wherein a product is heated for a fixed period of time in an energized condition and it is checked by various testing equipment to see whether or not a failure occurs.
FIG. 1 is a perspective view showing a conventional individual burn-in apparatus. Referring to FIG. 1, the conventional individual burn-in apparatus shown includes a testing equipment 4, an air conditioning unit 7, a connecting cable 11 and an individual burn-in chamber 200. The individual burn-in chamber 200 has a doorway 201 and includes a feeder apparatus 202.
The air conditioning unit 7 conditions air in the individual burn-in chamber 200 to a temperature suitable for a product to be tested.
The connecting cable 11 interconnects the testing equipment 4 and a product accommodated in the burn-in chamber 200, and the testing equipment 4 performs testing of the product to determine whether or not the product has something wrong. The testing equipment 4, however, does not perform all tests for the product, but performs only some required abridged tests (whether or not a self-diagnosis function, a voltage and so forth are normal).
The individual burn-in chamber 200 accommodates fixedly therein a product to be tested for a fixed period of time. The temperature of air in the individual burn-in chamber 200 is adjusted and maintained, controlled by the air conditioning unit 7, to a temperature suitable for a product to be tested so that the product accommodated in the individual burn-in apparatus 200 is heated to perform burn-in thereof while a testing operation is performed by the testing equipment 4.
The doorway 201 of the individual burn-in chamber 200 has a door provided therefor, and the door is opened only when a product is carried into or out from the individual burn-in chamber 200. The feeder apparatus 202 is accommodated fixedly in the individual burn-in chamber 200 and supplies electric power to a product to be burned in so as to keep the product in an energized condition during burning-in.
With the burn-in apparatus, a product for an object of testing is first carried into the individual burn-in chamber 200 by way of the doorway 201 the door of which is open, and is fixed in the individual burn-in chamber 200, and then, the door is closed. After then, the temperature of air in the individual burn-in chamber 200 is adjusted to a temperature suitable for testing by means of the air conditioning unit 7.
Then, the product fixedly accommodated in the individual burn-in apparatus 200 is supplied with electric power by the feeder apparatus 202 disposed in the individual burn-in chamber 200 so that it is thereafter kept in an energized condition.
Further, the product accommodated in the individual burn-in chamber 200 is heated by the air, which is kept conditioned to the temperature suitable for testing of the product in the individual burn-in chamber 200, so that it may be burned in. The product is connected to the testing equipment 4 by way of the connecting cable 11.
After then, while the product is burned in in the individual burn-in chamber 200, only some required abridged tests are performed by the testing equipment 4 to check whether or not the product has some defect.
FIG. 2 is a perspective view showing a conventional unmanned burn-in apparatus of the conveyor type. Referring to FIG. 2, the unmanned burn-in apparatus shown includes a testing equipment 4, three air conditioning units 7, a connecting cable 11 and a burn-in chamber 210. The burn-in chamber 210 has an entrance 212 and an exit 213 for a product at opposing portions thereof, and the unmanned burn-in apparatus of the conveyor type further includes an automatic conveyor 211 extending through the burn-in chamber 210 between and farther than the entrance 212 and the exit 213. The automatic conveyor 211 includes several feeder apparatus 214.
Here, the testing equipment 4, the air conditioning units 7 and the connecting cable 11 are individually constructed substantially similarly to those of the individual burn-in apparatus of FIG. 1 described above.
The burn-in chamber 210 accommodates therein a product to be burned in, and the temperature of air in the burn-in chamber 210 is adjusted and maintained adjusted by the air conditioning unit 7 to a temperature suitable for a product to be tested so that the product accommodated in the burn-in chamber 210 is heated to perform burn-in thereof.
The entrance 212 has a door provided therefor, and the door is opened only when a product is carried into the burn-in chamber 210. Also, the exit 213 has a door provided therefor, and the door is opened only when a product is carried out from the burn-in chamber 210.
The automatic conveyor 211 carries products successively into the burn-in chamber 210 by way of the entrance 212 and dynamically moves the products in the burn-in chamber 210 from the entrance 212 to the exit 213 of the burn-in chamber 210. The automatic conveyor 211 then feeds the products successively to the testing equipment 4 by way of the exit 213 of the burn-in chamber 210.
The feeder apparatus 214 supply electric power to products to be burned in which are placed on the automatic conveyor 211 and keep the products in an energized condition during burning in.
With the unmanned burn-in apparatus of the conveyor type, the air conditioning units 7 first conditions air in the burn-in chamber 210 to a temperature suitable for a product to be tested.
Then, products are successively accommodated into the burn-in chamber 210 from the entrance 212 side by the automatic conveyor 213 by way of the entrance 212, the door of which is open, and after such accommodation of the products is completed, the door is closed. Further, the products are individually supplied with electric power by the feeder apparatus 214.
In this instance, the products successively accommodated into the burn-in chamber 210 by the automatic conveyor 211 are heated by air, which is kept in the burn-in chamber 210 and conditioned to a temperature suitable for a product to be tested, so that they are burned in.
Then, after such burn-in, each of the products is carried out from the burn-in chamber 210 by the automatic conveyor 211 by way of the exit 213 of the burn-in chamber 210, the door of which is open, and after then, the door of the exit 213 is closed.
The product carried out from the burn-in chamber 210 in this manner is fed to the testing equipment 4 and then connected to the testing apparatus 4 by way of the connecting cable 11, whereafter only some required abridged tests are performed to check whether or not the product has some defects.
FIG. 3 is a perspective view showing a conventional unmanned burn-in apparatus of the horizontal circulating rack type. Referring to FIG. 3, the conventional unmanned burn-in apparatus of the horizontal circulating rack type includes a testing equipment 4, a connecting cable 11, three air conditioning units 7, a burn-in chamber 220, a lift apparatus 221 and an automatic conveyor 222. The burn-in chamber 220 has a doorway 223 and includes a burn-in storage 224 of the horizontal circulating rack type. The burn-in storage 224 of the horizontal circulating rack type includes a plurality of feeder apparatus 225.
Here, the testing equipment 4, the connecting cable 11 and the air conditioning units 7 are constructed substantially similarly to those of the burn-in apparatus of FIG. 2, and the automatic conveyor 222 successively transports products to the lift apparatus 221 and further transports products placed thereon by the lift apparatus 221 to the testing equipment 4.
The lift apparatus 221 moves upwardly or downwardly and takes out a product from the automatic conveyor 222 or from one of racks of the burn-in storage 224 of the horizontal circulating rack type, carries the thus taken out product upwardly or downwardly and places or accommodates the product onto the automatic conveyor 222 or one of the racks of the burn-in storage 224 of the horizontal circulating rack type.
The burn-in chamber 220 maintains the temperature of air in the burn-in chamber 220 which is conditioned to a temperature suitable for a product to be tested by the air conditioning unit 7 so as to heat products placed on the racks of the burn-in storage 224 of the horizontal circulating rack type in the burn-in chamber 220. Meanwhile, the doorway 223 has a door provided therefor, and the door is opened only when a product is to be carried into or out from the burn-in chamber 220.
The burn-in storage 224 of the horizontal circulating rack type literally is a horizontally circulating rack arrangement having a plurality of racks disposed in three horizontal rows on which products are to be placed and energized. The racks are disposed along a circular path and circulated horizontally on the circular path thereby so that a required rack may be transported to the doorway 223 of the burn-in chamber 220.
A feeder apparatus 225 is provided for each of the racks of the burn-in storage 224 of the horizontal circulating rack type and supplies electric power to a product placed on the corresponding rack of the burn-in storage 224 of the horizontal circulating rack type so as to keep the product in an energized condition during burning in.
With the unmanned burn-in apparatus of the horizontal circulating rack type, the air conditioning units 7 first condition air in the burn-in chamber 224 to a temperature suitable for a product to be tested.
Products are successively carried to a position in front of the lift apparatus 221 by the automatic conveyor 222, taken out from the automatic conveyor 222 by the lift apparatus 221, carried to a position in front of a selected one of the racks of the burn-in storage 224 of the horizontal circulating rack type by the lift apparatus 221, and placed onto the selected rack through the doorway 223 the door of which is open. After each product is placed onto such selected rack, the door of the doorway 223 is closed. Then, the product placed on the selected rack of the burn-in storage 224 of the horizontal circulating rack type is supplied with electric power from the corresponding feeder apparatus 225 so that it is thereafter kept in an energized condition.
In this manner, several products are placed onto selected racks of the burn-in storage 224 of the horizontal circulating rack type in the burn-in chamber 220 by the automatic conveyor 222 and the lift apparatus 221.
The products placed on the racks of the burn-in storage 224 of the horizontal circulating rack type in this manner are heated by air, which is maintained in the burn-in chamber 220 and conditioned to a temperature suitable for a product to be tested, while they are kept in an energized condition wherein they are supplied with electric power so that they may be burned in.
The products placed on the racks of the burn-in storage 224 of the horizontal circulating rack type after burn-in are successively carried to a position forwardly of the doorway 223 of the burn-in chamber 220 as the racks of the burn-in storage 224 are circulated horizontally. After then, the products are successively taken out from the burn-in storage 224 by the lift apparatus 221 through the doorway 223 the door of which is open, and then placed onto the automatic conveyor 222. After each product is placed on to the automatic conveyor 222, the door of the doorway 223 is closed.
Each of the products successively placed onto the automatic conveyor 222 in this manner are subsequently carried to the testing equipment 4 by the automatic conveyor 222 and connected to the testing equipment 4 by way of the connecting cable 11. After then, only some required abridged tests are performed by the testing equipment 4 to check whether or not the product has some defects.
The conventional burn-in apparatus described above with reference to FIGS. 1 to 3 have such several drawbacks as described below.
In particular, with the individual burn-in apparatus of FIG. 1, since a product is fixedly accommodated in the individual burn-in chamber and supplied with electric power and it is checked during burn-in of the product by the testing equipment whether or not the product has some defects, both of a product which fails completely during burn-in and another product which operates but unstably and suffers from a failure only during burn-in (making a factor of an initial failure after delivery to a customer) can be found out. However, since a set of testing equipments are required for a single product, a high cost of equipment is required.
Meanwhile, with the unmanned burn-in apparatus of-the conveyor type of FIG. 2 and the unmanned burn-in apparatus of the horizontal circulating rack type of FIG. 3, since burn-in of a large number of products can be performed by means of a burn-in chamber, the small number of air conditioning units and testing equipment is required. Also, burn-in can be performed in a high efficiency with regard to the quantity of products as compared to the individual burn-in apparatus and the cost of equipment required for inspection of telecommunication appliance products is much lower than that of the individual burn-in apparatus. However, since carrying of products into and out from the burn-in chamber is performed automatically, the automatic conveyor and the horizontal circulating racks operate every time, and consequently, the connecting cable for interconnecting products in the burn-in chamber and the testing equipment outside the burn-in chamber cannot be connected. As a result, presence or absence of defects cannot be checked by means of the testing equipment during burn-in.
Therefore, while a product which has failed completely during burn-in can be found out by a check of the testing equipment after completion of burn-in, a product which operates but unstably and suffers from a failure only when it is in a warm or heated condition during burn-in (making a factor of an initial failure after delivery to a customer) cannot be found out.